摘 要 近代塑膠製品主要以射出成型為主流,其具備製程多樣性、成本低及量產速度快等優勢,而模溫控制技術為影響品質之關鍵因素。高模溫可有效提升表面品質改善不良缺陷,再搭配動態模溫控制可於充填階段提高模溫並快速冷卻有縮短成型週期之功效,為現今主要發展之關鍵技術。動態模溫中因快速加熱與冷卻使模溫不穩定,影響成品穩定性,因此模具溫度監視與精準加熱控制為主要研究之方向。 本研究中,採感應加熱動態模溫控制,單獨模板加熱與實際成型進行加熱時間(s)及目標加熱溫度(℃)兩種控制實驗。一、控制加熱時間以推估穩定模溫之加熱範圍。二、設定欲達成之目標溫度,隨著溫度變化修正加熱時間,控制達目標溫度之加熱範圍。利用溫度感測器偵測及記錄模溫變化,將動態模溫控制結果與傳統模溫控制比較其模溫穩定性。 研究顯示,單獨加熱模板以固定或不同加熱時間加熱模溫90℃之公母模,因公模冷卻設計較母模佳,故加熱模板之母模平均溫升18℃/s,公模3.9℃/s。比較母模溫度曲線,實際成型較加熱模板之充填溫度高5.7℃。以母模溫度90℃進行三種不同溫控實驗,由實驗結果之溫度曲線比較,目標溫度曲線需166s達穩定平均溫度121.6℃,固定加熱時間控制需266s達穩定平均溫度119.6℃,傳統溫控需1107s達穩定平均溫度96.1℃。目標溫度控制模式較固定加熱時間快達到模溫穩定,易受冷卻效率及低模溫影響,造成大幅溫升溫降情形,固定加熱時間則以漸近且穩定不受冷卻及模溫所影響。由實驗結果可透過模溫監控搭配動態模溫,可達到快速加熱及穩定模溫之成效。 關鍵字:感應加熱、動態模溫控制、射出成型、模溫監控
ABSTRACT In this Study, both mold surface temperature monitoring and electromagnetic induction heat controlling combined with software controlling are developed to achieve a dynamic mold surface steady temperature. The temperature sensor was installed on away from 1mm of mold surface for temperature monitoring. Then we set up two experiments for which with and without injection molding. One was fixed the heating time and estimated the heating range, another was fixed the highest temperature and .controlled the heating range by amending the heating time. At last we measured the mold surface temperature by sensors and compared the results of mold temperature with conventional mold temperature control. As a result, the core and cavity can be heated to 3.9℃/s and 18℃/s individually by induction heating without injection molding. Then we compare it with injection molding, the temperature of cavity is higher (about 5.7℃). According to the curve of temperature, it needs 166s to reach the aim minimum average steady temperature (121.6℃). And we need 266s to reach the aim minimum average steady temperature (119.6℃) when we fixing the heating time and it needs 1107s to reach aim minimum average steady temperature (96.1℃) under conventional temperature control. The mold temperature can reach the steady average temperature rapidly by using aim temperature control, but the temperature is more stably by fix the heating time. Finally, we can heat rapidly and stably by using induction heating and monitor it. Keywords: Induction Heating, Dynamic Mold Temperature Control, Injection Molding, Mold Temperature Monitor and Control